DTC 56
DTC 56: G-sensor (Lateral) System (Open Circuit or Short Circuit)G-sensor (Lateral) System Circuit <Vehicles without ABS>:
G-sensor (Lateral) System Circuit <Vehicles with ABS>:
CIRCUIT OPERATION
The AWD-ECU receives the acceleration level of the vehicle in the right/left direction from the G-sensor (lateral).
DTC SET CONDITIONS
DTC 56 is set when the output signal of the G-sensor (lateral) is below 0.5 volts or above 4.5 volts.
TROUBLESHOOTING HINTS (THE MOST LIKELY CAUSES FOR THIS CODE TO BE SET ARE:)
^ Malfunction of the G-sensor (lateral)
^ Damaged harness and connector
^ Malfunction of the ABS-ECU
^ Malfunction of the AWD-ECU
DIAGNOSIS
Required Special Tool:
^ MB991958: Scan Tool (M.U.T-III Sub Assembly)
^ MB991824: V.C.I.
^ MB991827: USB Cable
^ MB991911: Main Harness B
STEP 1. Using scan tool MB991958, check data list item 15: G-sensor (Lateral) Voltage.
CAUTION: To prevent damage to scan tool MB991958, always turn the ignition switch to the LOCK (OFF) position before connecting or disconnecting scan tool MB991958.
1) Connect scan tool MB991958 to the data link connector.
2) Turn the ignition switch to ON position.
3) Set scan tool MB991958 to the data reading mode. Item 15: G-sensor (Lateral) Voltage.
^ When the vehicle is stopped (horizontal), voltage of 2.4 Volts - 2.6 Volts is displayed.
^ The voltage will fluctuate around 2.5 Volts while driving.
4) Turn the ignition switch to the LOCK (OFF) position.
Q: Is the sensor operating properly?
YES: It can be assumed that this malfunction is intermittent.
NO: Go to Step 2.
STEP 2. Measure the voltage at G-sensor (lateral) connector D-37.
1) Disconnect the G-sensor (lateral) connector, and measure the voltage between terminal 1 and ground.
2) Turn the ignition switch to the ON position.
^ The voltage should measure battery positive voltage.
Q: Is the measured voltage battery positive voltage?
YES: Go to Step 7.
NO: Go to Step 3.
STEP 3. Check junction block connector C-211, C-214 and G-sensor (lateral) connector D-37 for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Q: Are the connectors and terminals in good condition?
YES: Go to Step 4.
NO: Repair or replace the damaged components.
STEP 4. Check the harness for open circuit or short circuit to ground between ignition switch and G-sensor (lateral) connector D-37 terminal 1.
Q: Is the harness wire in good condition?
YES: Go to Step 5.
NO: Repair or replace the harness wire.
STEP 5. Using scan tool MB991958, read the ACD diagnostic trouble code.
CAUTION: To prevent damage to scan tool MB991958, always turn the ignition switch to the LOCK (OFF) position before connecting or disconnecting scan tool MB991958.
1) Connect scan tool MB991958 to the data link connector.
2) Turn the ignition switch to the ON position.
3) Check for ACD diagnostic trouble code.
4) Turn the ignition switch to the LOCK (OFF) position.
Q: Is DTC 56 set?
YES: Go to Step 6.
NO: The procedure is complete.
STEP 6. Using scan tool MB991958, check data list item 15: G-sensor (Lateral) Voltage.
1) Connect scan tool MB991958 to the data link connector.
2) Turn the ignition switch to ON position.
3) Set scan tool MB991958 to the data reading mode.
^ Item 15: G-sensor (Lateral) Voltage.
^ When the vehicle is stopped (horizontal), voltage of 2.4 Volts - 2.6 Volts is displayed.
^ The voltage will fluctuate around 2.5 Volts while driving.
4) Turn the ignition switch to the LOCK (OFF) position.
Q: Is the sensor operating properly?
YES: It can be assumed that this malfunction is intermittent.
NO: Replace the AWD-ECU.
STEP 7. Measure the resistance at G-sensor (lateral) connector D-37 by backprobing.
Disconnect the G-sensor (lateral) connector, and measure the resistance between terminal 3 and ground.
^ The resistance should measure less than 2 ohms
Q: Is the measured resistance less than 2 ohms?
YES: Go to Step 12.
NO: Go to Step 8.
STEP 8. Check ABS-ECU connector B-118
Q: Are the connectors and terminals in good condition?
YES: Go to Step 9.
NO: Repair or replace the damaged components.
STEP 9. Check the harness for open circuit between ABS-ECU connector B-118 terminal 24 and G-sensor (lateral) connector D-37 terminal 3
Q: Is the harness wire in good condition?
YES: Go to Step 10.
NO: Repair or replace the harness wire.
STEP 10. Using scan tool MB991958, read the ACD diagnostic trouble code.
CAUTION: To prevent damage to scan tool MB991958, always turn the ignition switch to the LOCK (OFF) position before connecting or disconnecting scan tool MB991958.
1) Connect scan tool MB991958 to the data link connector.
2) Turn the ignition switch to the ON position.
3) Check for ACD diagnostic trouble code.
4) Turn the ignition switch to the LOCK (OFF) position.
Q: Is DTC 56 set?
YES: Go to Step 11.
NO: The procedure is complete.
STEP 11. Using scan tool MB991958, check data list item 15: G-sensor (Lateral) Voltage.
1) Connect scan tool MB991958 to the data link connector.
2) Turn the ignition switch to ON position.
3) Set scan tool MB991958 to the data reading mode.
^ Item 15: G-sensor (Lateral) Voltage.
^ When the vehicle is stopped (horizontal), voltage of 2.4 Volts - 2.6 Volts is displayed.
^ The voltage will fluctuate around 2.5 Volts while driving.
4) Turn the ignition switch to the LOCK (OFF) position.
Q: Is the sensor operating properly?
YES: It can be assumed that this malfunction is intermittent.
NO
NO
STEP 12. Measure the voltage at G-sensor (lateral) connector D-37.
1) Remove the G-sensor (lateral) connector, and connect special tool harness set (MB991348) between the disconnected connectors.
2) Turn the ignition switch to the ON position.
3) Measure the voltage between terminal 2 and ground.
^ When the label on the G-sensor (Lateral) is horizontal, voltage of 2.4 Volts & 2.6 Volts is displayed.
^ When the label on the G-sensor (Lateral) is vertical, voltage of 3.3 Volts - 3.7 Volts is displayed.
4) Turn the ignition switch to the LOCK (OFF) position.
Q: Is the check result normal?
YES: Go to Step 13.
NO: Replace the G-sensor (lateral).
STEP 13. Check ABS-ECU connector B-118
Q: Are the connectors and terminals in good condition?
YES: Go to Step 14.
NO: Repair or replace the damaged components.
STEP 14. Check the harness for open circuit or short circuit to ground between AWD-ECU connector C-139 terminal 11 and G-sensor (lateral) connector D-37 terminal 2.
Q: Is the harness wire in good condition?
YES
YES
NO: Repair or replace the harness wire.
STEP 15. Check the harness for short circuit to ground between ABS-ECU connector B-1 18 terminal 14 and G-sensor (lateral) connector D-37 terminal 2.
Q: Is the harness wire in good condition?
YES: Go to Step 6.
NO: Repair or replace the harness wire.